394, WARREN UPHAM, ESQ., M.A., F.G.S.A., ON 
tinctive name, “the Champlain epoch,” referrmg to the 
occurrence of fossiliferous marine beds overlying the glacial 
diift in the basin of Lake Champlain. It was the time of 
land depression from the high epeirogenic uplift that had 
caused the snow and ice accumulation. Thereby a temperate 
climate, warm in the summers, was restored on the borders 
of the ice-sheet, which retreated rapidly, though waveringly. 
More vigorous g elacial currents were then produced by ‘the 
marginal melting and increased steepness of the ice-front, 
favouring the formation of many retreatal moraines of very 
hummocky and boulder-bearing drift. 
The continuous Glacial period or Ice age may be therefore 
regarded as divisible into two chief parts or stages, which 
were of quite unequal length, the first being probably at 
least ten times as long as the second. The first or Glacial 
stage was marked by high clevation of the drift-bearmg 
areas, alike in America and Europe, and by their envelopment 
beneath vast ice-sheets, which varied much in their extent. 
during successive long periods of alternating advance and 
recession. The second or Champlain stage was distinguished 
by the subsidence of these areas and the departure of "the ice 
with abundant deposition of both glacial and modified drift. 
Epeirogenic movements, first of great uplift and later ot 
depression, were thus the basis of the chief time divisions of 
this period. One was the time mainly characterized by the 
extension and culmination of glaciation; the other mecluded 
its wavering decline and end. Each of these periods, as they 
may be named (although merely noting the general growth 
and general wane of the ice-sheets) was divided into stages, 
marked in the glacial epoch by fluctuations of the pre- 
dominant ice accumulation, and in the Champlain period by 
successively diminishing limits of glaciation, by retreatal 
moraines, and by glacial lakes temporarily held in basins 
that sloped toward the departing ice. 
Exploration of the European glacial drift by two 
Americans, Professor H. Carvill Lewis in the British Isles 
and Professor R. D. Salisbury in Germany, laid the founda- 
tions for determining the geologic equivalency of the 
successive parts of the North American and European drift 
series. Salisbury especially noted that the marginal 
moraines of northern Germany lie, as in the United States, 
at some distance back from the limits of the drift. 
Studies by many observers have shown that on both 
continents the border of the drift along the greater part 
